miR-181-5p attenuates neutrophilic inflammation in asthma by targeting DEK.

We investigated the regulatory role of miR-181b-5p in neutrophilic asthma and its mechanisms by targeting DEK. DEK, matrix metalloproteinase (MMP)-2, and MMP-9 were overexpressed and the miR-181b-5p was decreased in mice with neutrophilic asthma. DEK was a direct target of miR-181b-5p. In mouse model, miR-181b-5p agomir had an inhibitory effect on airway inflammation and remodeling. miR-181b-5p inhibited DEK/p-GSK-3ßSer9/ß-catenin/MMP-9 pathway activation by regulating Wnt ligands in BEAS-2B and 16HBE cells. The ability of supernatants from human bronchial epithelial cells (hBECs) co-stimulated with CXCL8 (IL-8) and miR-181b-5p to induce NETs was weaker than that of IL-8 alone. Moreover, DEK overexpression led to excessive mitochondrial dysfunction, including DRP1 up-regulation, p-DRP1ser637 and MFN2 down-regulation, mitochondrial membrane potential loss, excessive mtROS generation and mitochondrial incompleteness. Interestingly, all these phenotypes were rescued by Wnt inhibitor DKK-1 and miR-181b-5p agomir. Additionally, inhibition of DRP1 with Mdivi-1 decreased MMP-9 on BEAS-2B cells. Overall, miR-181b-5p could attenuate neutrophilic asthma through inhibition of NETs release, DEK/p-GSK-3ßSer9/ß-catenin/MMP-9 pathway, DEK/Wnt/DRP1/MMP-9 and mitochondria damage. It may become a new therapeutic target for neutrophilic asthma.

Protective effects of glaucocalyxin A on the airway of asthmatic mice.

The aim of this study is to investigate the protective effects of glaucocalyxin A (GLA) on airways in mouse models of asthma, concerning the inflammatory mediators, Th1/Th2 subgroup imbalance, and Toll-like receptor 4 (TLR4)/NF-κB signaling pathway. Hematoxylin and eosin/periodic acid-Schiff staining was used to observe the pathological changes in lung tissues. Inflammatory cytokine contents in the bronchoalveolar lavage fluid were detected by enzyme-linked immunosorbent assay. Protein expression levels were detected with Western blot, immunohistochemistry, and immunofluorescence. In vivo studies showed that, in ovalbumin (OVA)-induced asthmatic mouse models, the GLA treatments reduced the airway hyperresponsiveness and the secretion of inflammatory cells, declined the proliferation of goblet cells, decreased the levels of IL-4, IL-5, and IL-13, and increased the contents of interferon-γ and IL-12. Moreover, GLA inhibited the protein expression levels of TLR4, MyD88, TRAF6, and NF-κB in OVA-induced asthmatic mouse models. Further in vitro studies showed that GLA inhibited the expression of NF-κB, p-IκBα, tumor necrosis factor-α, IL-6, and IL-1ß and blocked the nuclear transfer of NF-κB in lipopolysaccharide-stimulated RAW264.7 macrophages. Conclusively, GLA can inhibit the inflammatory responses in OVA-induced asthmatic mice and inhibit the release of inflammatory factors in LPS-induced RAW264.7 macrophages, which may be related to the inhibition of TLR4/NF-κB signaling pathway.

MicroRNA-182-5p Attenuates Asthmatic Airway Inflammation by Targeting NOX4.

Bronchial asthma is characterized by chronic airway inflammation, airway hyperresponsiveness, and airway remodeling. MicroRNA (miRNA) has recently been implicated in the pathogenesis of asthma. However, the mechanisms of different miRNAs in asthma are complicated, and the mechanism of miRNA-182-5p in asthma is still unclear. Here, we aim to explore the mechanism of miRNA182-5p in asthma-related airway inflammation. Ovalbumin (OVA)-induced asthma model was established. MiRNA Microarray Analysis was performed to analyze the differentially expressed miRNAs in the asthma model. We found that the expression of miRNA-182-5p was significantly decreased in OVA-induced asthma. In vitro, IL-13 stimulation of BEAS-2B cells resulted in a significant up-regulation of NOX4 (nicotinamide adenine dinucleotide phosphate oxidase 4), accompanied by mitochondrial damage-induced apoptosis, NLRP3 (NOD-like receptor family pyrin domain-containing 3)/IL-1ß activation, and reduced miRNA-182-5p. In contrast, overexpression of miRNA-182-5p significantly inhibited epithelial cell apoptosis and NLRP3/IL-1ß activation. In addition, we found that miRNA-182-5p could bind to the 3' untranscripted region of NOX4 mRNA and inhibit epithelial cell inflammation by reducing oxidative stress and mitochondrial damage. In vivo, miRNA-182-5p agomir treatment significantly reduced the percentage of eosinophils in bronchoalveolar lavage fluid, and down-regulated Th2 inflammatory factors, including IL-4, IL-5, and OVA induced IL-13. Meanwhile, miRNA-182-5p agomir reduced the peribronchial inflammatory cell infiltration, goblet cell proliferation and collagen deposition. In summary, targeting miRNA-182-5p may provide a new strategy for the treatment of asthma.

Sesamin Alleviates Asthma Airway Inflammation by Regulating Mitophagy and Mitochondrial Apoptosis.

Bronchial asthma poses a considerable burden on both individual patients and public health. Sesamin is a natural lignan that relieves asthma. However, the potential regulatory mechanism has not been fully validated. In this study, we revealed the mechanism of sesamin in inhibiting airway inflammation of asthma. In cockroach extract (CRE)-induced asthmatic mice, sesamin efficiently inhibited inflammatory cell infiltration, expressions of total and CRE-specific IgE in serum, and inflammatory cytokines (including IL-4, 5, 13) in bronchoalveolar lavage fluid. Further study revealed that sesamin inhibited Th2 cells in the mediastinal lymph nodes and spleen, the expression of PTEN-induced putative kinase 1 (PINK1) and Parkin, and apoptosis of lung airway epithelial cells. In vitro, sesamin had no significant cytotoxicity to BEAS-2B cells. Sesamin significantly increased TNF-α/IL-4-induced superoxide dismutase (SOD), catalase (CAT), heme oxygenase 1 (HO-1), and nuclear factor erythroid 2 related factor 2 (Nrf2), and decreased malondialdehyde. Sesamin also inhibited TNF-α/IL-4-induced mitochondrial reactive oxygen species, increased mitochondrial membrane potential, and reduced cell apoptosis as well as PINK1/Parkin expression and translocation to mitochondria. Conclusively, sesamin may relieve asthma airway inflammation by inhibiting mitophagy and mitochondrial apoptosis. Thus, sesamin may become a potential therapeutic agent for asthma.

[DEK-targeting aptamer DTA-64 inhibits epithelial-mesenchymal transition of airway epithelial cells in bronchial asthmatic mice via blocking TGF-ß1 signaling pathway].

Objective To investigate the inhibitory effect of DEK targeting aptamer 64 (DTA-64) on airway inflammation and epithelial to mesenchymal transition (EMT) induced by ovalbumin (OVA) in asthmatic mice. Methods Thirty-two female BALB/c mice (8 weeks old) were randomly divided into PBS group, OVA model group, DTA-64 group (1 µg/mouse), and control aptamer group, with 8 in each. HE staining of lung tissues was used to detect inflammatory cell infiltration around the airways; immunohistochemical staining was used to detect DEK expression around the airways; ELISA was used to detect serum IgE, and Th2-type cytokines IL-4, IL-5, IL-13 and Th1-type cytokine IFN-γ in bronchoalveolar lavage fluid (BALF); Western blot was applied to detect the EMT-related proteins α-SMA, Snail+Slug, vimentin, and E-cadherin, and TGF-ß1/Smad, MAPK, PI3K, AKT, as well as mTOR in lung; and flow cytometry was used to observe the α-SMA expression in the lung single cell suspensions. Results DEK protein was highly expressed in the lung tissues of OVA group mice and decreased in the DTA-64 group mice; DTA-64 reduced the infiltration of eosinophils and neutrophils around the airways, down-regulated serum OVA-specific IgE and IL-4, IL-5, IL-13 in BALF, and up-regulated IFN-γ; DTA-64 also reduced the expressions of vimentin, α-SMA, Snail+Slug in the lung tissue, and up-regulated epithelial marker E-cadherin. DTA-64 inhibited the expressions of TGF-ß1 and its downstream canonical pathways Smad2/3 and Smad4, as well as the phosphorylation of non-canonical TGF-ß1 pathways ERK1/2, p38 MAPK, JNK and PI3K/AKT/mTOR. Conclusion DTA-64 may inhibit the airway inflammation and EMT induced by OVA in asthmatic mice via blocking TGF-ß1/Smad, MAPK and PI3K signaling pathways, thereby alleviating airway remodeling in asthma.

Pterostilbene suppresses oxidative stress and allergic airway inflammation through AMPK/Sirt1 and Nrf2/HO-1 pathways.

INTRODUCTION: Pterostilbene (Pts) may be used for allergic asthma treatment. The AMPK/Sirt1 and Nrf2/HO-1 pathways are potential targets for asthma treatement. However, the relationship between Pts and AMPK/Sirt1 and Nrf2/HO-1 pathways in asthma is unclear. Herein, we aim to explore the pharmacological effects of Pts on oxidative stress and allergic inflammatory response as well as the mechanism involving AMPK/Sirt1 and Nrf2/HO-1 pathways. METHODS: Asthma model was established in mice with ovalbumin (OVA). The model mice were treated by different concentrations of Pts. Lung pathological changes were observed through histological staining. In vitro, lipopolysaccharide (LPS)-stimulated 16HBE cells were treated with Pts. The siAMPKα2, siSirt1 and siNrf2 knockdown, and treatment with compound C, EX-527 or ML385 were also performed in 16HBE cells. Enzyme-linked immunosorbent assay was used to detect interleukin-4 (IL-4), IL-13, IL-5, total and OVA specific immunoglobulin E (IgE), and interferon γ (IFN-γ). Pneumonography was used to measure the airway hyperreactivity (AHR). Superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) levels were also detected. Immunohistochemistry, Western blot and immunofluorescence were used to measure protein levels. RESULTS: Pts significantly attenuated lung inflammatory cell infiltration and goblet cell proliferation. Meanwhile, Pts treatment could reduce IL-4, IL-13, IL-5, and IgE (total and OVA specific) levels in the asthma model mice. However, IFN-γ in bronchoalveolar lavage fluid was elevated. In addition, Pts reduced AHR. We also found that Pts treatment promoted serum SOD and CAT, and reduced MDA. In vitro results showed that Pts treatment promoted iNOS, TNF-α, COX-2, IL-1ß, and IL-6 expressions in 16HBE cells, prolonged G0/G1 phase of the cell cycle, and resulted in a shortened G2M phase. Moreover, we found that Pts promoted the phosphorylation of AMPK in 16HBE, and meanwhile inhibited the increase of ROS induced by LPS. Additionally, Pts treatment inhibited p-AMPK, Sirt1, Nrf2 and HO-1, which in turn leads to the alleviation of AMPK/Sirt1 and Nrf2/HO-1 pathways. CONCLUSION: Pts alleviated oxidative stress and allergic airway inflammation via regulation of AMPK/Sirt1and Nrf2/HO-1 signaling pathways.

Glaucocalyxin A Attenuates Allergic Responses by Inhibiting Mast Cell Degranulation through p38MAPK/NrF2/HO-1 and HMGB1/TLR4/NF-κB Signaling Pathways.

Glaucocalyxin A (GLA) has various pharmacological effects like antioxidation, immune regulation, and antiatherosclerosis. Here, in this study, the effect and mechanism of GLA on mast cell degranulation were studied. The results of the anti-DNP IgE-mediated passive cutaneous anaphylaxis (PCA) showed that GLA dramatically inhibited PCA in vivo, as evidenced by reduced Evans blue extravasation and decreased ear thickness. In addition, GLA significantly reduced the release of histamine and ß-hexosaminidase, calcium influx, cytokine (IL-4, TNF-α, IL-1ß, IL-13, and IL-8) production in the RBL-2H3 (rat basophilic leukemia cells), and RPMCs (peritoneal mast cells) in vitro. Moreover, we further investigated the regulatory mechanism of GLA on antigen-induced mast cells by Western blot, which showed that GLA inhibited FcεRI-mediated signal transduction and invalidated the phosphorylation of Syk, Fyn, Lyn, Gab2, and PLC-γ1. In addition, GLA inhibited the recombinant mouse high mobility group protein B1- (HMGB1-) induced mast cell degranulation through limiting nuclear translocation of NF-κBp65. Treatment of mast cells with siRNA-HMGB1 significantly inhibited HMGB1 levels, as well as MyD88 and TLR4, decreased intracellular calcium levels, and suppressed the release of ß-hexosaminidase. Meanwhile, GLA increased NrF2 and HO-1 levels by activating p38MAPK phosphorylation. Consequently, these data suggest that GLA regulates the NrF2/HO-1 signaling pathway through p38MAPK phosphorylation and inhibits HMGB1/TLR4/NF-κB signaling pathway to reduce mast cell degranulation and allergic inflammation. Our findings could be used as a promising therapeutic drug against allergic inflammatory disease.

Recombinant Pyrin Domain Protein Attenuates Airway Inflammation and Alleviates Epithelial-Mesenchymal Transition by Inhibiting Crosstalk Between TGFß1 and Notch1 Signaling in Chronic Asthmatic Mice.

This article aims to investigate the effects of recombinant pyrin domain (RPYD) on airway inflammation and remodeling in mice with chronic asthma. The chronic asthma BALB/c mouse model was first sensitized by ovalbumin (OVA) and then challenged by OVA nebulization. RPYD or dexamethasone was given before OVA challenge. Our results showed that RPYD significantly inhibited the increase of total cell number, eosinophils, neutrophils and lymphocytes in bronchoalveolar lavage fluid (BALF) induced by OVA, and reduced the infiltration of inflammatory cells, the proliferation of goblet cells and collagen deposition. In addition, RPYD inhibited the mRNA and protein levels of α-smooth muscle actin (α-SMA), transforming growth factor (TGF)-ß1, Jagged1, Notch1, Hes1 and Smad3, as well as Smad3 phosphorylation. TGFß1 down-regulated the level of E-cadherin and promoted the expression of α-SMA, thus inducing epithelial-mesenchymal transition (EMT) in bronchial epithelial cells. We found that RPYD reduced EMT by inhibiting TGFß1/smad3 and Jagged1/Notch1 signaling pathways. Further overexpression of NICD showed that under the stimulation of TGFß1, NICD enhanced the phosphorylated Smad3 and nuclear Smad3, accompanied by the increased expression of Notch1 target gene Hes1. In contrast, after treatment with smad3 siRNA, the expression of Hes1 was down regulated as the decrease of Smad3, which indicates that there is crosstalk between smad3 and NICD on Hes1 expression. In conclusion, RPYD reduces airway inflammation, improves airway remodeling and reduces EMT in chronic asthmatic mice by inhibiting the crosstalk between TGFß1/smad3 and Jagged1/Notch1 signaling pathways.

DEK-targeting aptamer DTA-64 attenuates bronchial EMT-mediated airway remodelling by suppressing TGF-ß1/Smad, MAPK and PI3K signalling pathway in asthma.

This study is to investigate the inhibitory effects and mechanisms of DEK-targeting aptamer (DTA-64) on epithelial mesenchymaltransition (EMT)-mediated airway remodelling in mice and human bronchial epithelial cell line BEAS-2B. In the ovalbumin (OVA)-induced asthmatic mice, DTA-64 significantly reduced the infiltration of eosinophils and neutrophils in lung tissue, attenuated the airway resistance and the proliferation of goblet cells. In addition, DTA-64 reduced collagen deposition, transforming growth factor 1 (TGF-ß1) level in BALF and IgE levels in serum, balanced Th1/Th2/Th17 ratio, and decreased mesenchymal proteins (vimentin and α-SMA), as well as weekend matrix metalloproteinases (MMP-2 and MMP-9) and NF-κB p65 activity. In the in vitro experiments, we used TGF-ß1 to induce EMT in the human epithelial cell line BEAS-2B. DEK overexpression (ovDEK) or silencing (shDEK) up-regulated or down-regulated TGF-ß1 expression, respectively, on the contrary, TGF-ß1 exposure had no effect on DEK expression. Furthermore, ovDEK and TGF-ß1 synergistically promoted EMT, whereas shDEK significantly reduced mesenchymal markers and increased epithelial markers, thus inhibiting EMT. Additionally, shDEK inhibited key proteins in TGF-ß1-mediated signalling pathways, including Smad2/3, Smad4, p38 MAPK, ERK1/2, JNK and PI3K/AKT/mTOR. In conclusion, the effects of DTA-64 against EMT of asthmatic mice and BEAS-2B might partially be achieved through suppressing TGF-ß1/Smad, MAPK and PI3K signalling pathways. DTA-64 may be a new therapeutic option for the management of airway remodelling in asthma patients.

[Recombinant pyrin domain protein attenuates airway inflammation and airway remodeling through TGF-ß1/SMAD and Jagged1/Notch1 signaling pathways in chronic bronchial asthma mice].

Objective To investigate whether the recombinant pyrin domain protein can alleviate the airway inflammation and airway remodeling of OVA-induced mice with chronic asthma by inhibiting transforming growth factor ß1(TGF-ß1)/SMAD and Jagged1/Notch1 signaling pathways. Methods Thirty-two male BALB/c mice were selected and divided into 4 groups with 8 mice in each group. The four groups were the control group, OVA model group, recombinant pyrin domain protein treatment group (100 µg/kg), and the dexamethasone treatment group (1 mg/kg). Enzyme-linked immunosorbent assay (ELISA) was used to determine the expression of inflammatory factors in bronchoalveolar lavage fluid (BALF) of mice in each group. hematoxylin-eosin staining (HE) was used to observe the inflammatory infiltration of bronchus in mice. The changes of goblet cells were observed by periodic acid-Schiff (PAS) staining and collagen fibers by Masson staining. Immunohistochemical staining (IHC) was performed to observe the expression distribution of α smooth muscle actin (α-SMA), TGF-ß1 and Notch1 proteins in lung tissues. Western blotting was used to detect the protein levels of α-SMA, E-cadherin, TGF-ß1, SMAD2/3, SMAD7, Jagged1, Notch1 and Hes1 in lung tissues. Results The recombinant pyrin domain protein not only improved the airway inflammatory response of the OVA-induced mice with bronchial asthma, but also inhibited the hyperplasia of goblet cells and collagen fiber deposition, reduced the tumor necrosis factor α (TNF-α) in BALF, interleukin 1ß (IL-1ß), IL-4, IL-13 levels, and inhibited the protein expression of TGF-ß1, SMAD2/3, Jagged1, Notch1, Hes1 and α-SMA in lung tissues. Conclusion The recombinant pyrin domain protein can reduce the airway inflammation and airway remodeling of asthmatic mice by inhibiting TGF-ß1/SMAD and Jagged1/Notch1 signaling pathways.

Protective Effect and Mechanism of Alprostadil in Acute Respiratory Distress Syndrome Induced by Oleic Acid in Rats.

BACKGROUND This study investigated the role and mechanism of alprostadil in acute respiratory distress syndrome (ARDS) induced by oleic acid (OA) in rats. MATERIAL AND METHODS Sprague-Dawley rats were randomly divided into control, OA model, and OA + Alprostadil (2.5, 5, and 10 µg/kg, respectively) groups. The ARDS model was induced by femoral vein injection of OA, and alprostadil was administrated immediately. Lung injury was evaluated by lung wet-dry weight ratio (W/D) and histological analyses. Expressions of ACE, inflammatory mediators, apoptotic-related proteins, and proteins in the MAPKs and NF-κB signaling pathways were determined by Western blot or immunohistochemical staining. RESULTS Compared with the control group, the OA model group had significantly increased W/D, lung injury score, and collagen deposition at 3 h after OA injection. However, alprostadil (10 µg/kg) treatment significantly reduced OA-induced elevation of these indicators. Additionally, OA-induced expression of TNF-α and IL-1ß were suppressed by alprostadil. The OA-induced activation of nuclear factor (NF) κB p65 was also reduced by alprostadil. Furthermore, we found that Alprostadil had an inhibitory effect on the phosphorylation of JNK, ERK1/2, and p38 MAPKs. Alprostadil inhibited Bax but increased Bcl-2, indicating a suppressive role in apoptosis. Remarkably increased expression of ACE in the OA model group was observed, which was decreased by alprostadil. CONCLUSIONS Alprostadil has a protective effect on ARDS induced by OA in rats, possibly through inhibiting apoptosis, suppressing the activation of MAPKs and NF-κB signaling pathways, and decreasing ACE protein expression. Therefore, the use of alprostadil in clinical ARDS treatment is promising.